Amazon DBS-C01 Online Practice Questions and Exam Preparation

Amazon DBS-C01 Online Questions & Answers

• Question 231:

  A manufacturing company has an. inventory system that stores information in an Amazon Aurora MySQL DB cluster. The database tables are partitioned. The database size has grown to 3 TB. Users run one-time queries by using a SQL client. Queries that use an equijoin to join large tables are taking a long time to run.

  Which action will improve query performance with the LEAST operational effort?

  A. Migrate the database to a new Amazon Redshift data warehouse.
  B. Enable hash joins on the database by setting the variable optimizer_switch to hash_join=on.
  C. Take a snapshot of the DB cluster. Create a new DB instance by using the snapshot, and enable parallel query mode.
  D. Add an Aurora read replica.
  B. Enable hash joins on the database by setting the variable optimizer_switch to hash_join=on.

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  Explanation/Reference:

  https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.BestPra ctices.html

• Question 232:

  A company is using an Amazon ElastiCache for Redis cluster to host its online shopping website. Shoppers receive the following error when the website's application queries the cluster:

  

  Which solutions will resolve this memory issues with the LEAST amount of effort? (Choose three.)

  A. Reduce the TTL value for keys on the node.
  B. Choose a larger node type.
  C. Test different values in the parameter group for the maxmemory-policy parameter to find the ideal value to use.
  D. Increase the number of nodes.
  E. Monitor the EngineCPUUtilization Amazon CloudWatch metric. Create an AWS Lambda function to delete keys on nodes when a threshold is reached.
  F. Increase the TTL value for keys on the node.
  A. Reduce the TTL value for keys on the node.
  B. Choose a larger node type.
  C. Test different values in the parameter group for the maxmemory-policy parameter to find the ideal value to use.

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  Explanation/Reference:

  https://aws.amazon.com/premiumsupport/knowledge-center/oom-command- not-allowed-redis/

• Question 233:

  A large ecommerce company uses Amazon DynamoDB to handle the transactions on its web portal. Traffic patterns throughout the year are usually stable; however, a large event is planned. The company knows that traffic will increase by up to 10 times the normal load over the 3-day event. When sale prices are published during the event, traffic will spike rapidly.

  How should a Database Specialist ensure DynamoDB can handle the increased traffic?

  A. Ensure the table is always provisioned to meet peak needs
  B. Allow burst capacity to handle the additional load
  C. Set an AWS Application Auto Scaling policy for the table to handle the increase in traffic
  D. Preprovision additional capacity for the known peaks and then reduce the capacity after the event
  D. Preprovision additional capacity for the known peaks and then reduce the capacity after the event

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  Explanation/Reference:

  https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/bp-partition-key- design.html#bp-partition-key-throughput-bursting "DynamoDB provides some flexibility in your per-partition throughput provisioning by providing burst capacity. Whenever you're not fully using a partition's throughput, DynamoDB reserves a portion of that unused capacity for later bursts of throughput to handle usage spikes. DynamoDB currently retains up to 5 minutes (300 seconds) of unused read and write capacity. During an occasional burst of read or write activity, these extra capacity units can be consumed quickly--even faster than the per-second provisioned throughput capacity that you've defined for your table. DynamoDB can also consume burst capacity for background maintenance and other tasks without prior notice. Note that these burst capacity details might change in the future."

• Question 234:

  A company's development team needs to have production data restored in a staging AWS account. The production database is running on an Amazon RDS for PostgreSQL Multi-AZ DB instance, which has AWS KMS encryption enabled using the default KMS key. A database specialist planned to share the most recent automated snapshot with the staging account, but discovered that the option to share snapshots is disabled in the AWS Management Console.

  What should the database specialist do to resolve this?

  A. Disable automated backups in the DB instance. Share both the automated snapshot and the default KMS key with the staging account. Restore the snapshot in the staging account and enable automated backups.
  B. Copy the automated snapshot specifying a custom KMS encryption key. Share both the copied snapshot and the custom KMS encryption key with the staging account. Restore the snapshot to the staging account within the same Region.
  C. Modify the DB instance to use a custom KMS encryption key. Share both the automated snapshot and the custom KMS encryption key with the staging account. Restore the snapshot in the staging account.
  D. Copy the automated snapshot while keeping the default KMS key. Share both the snapshot and the default KMS key with the staging account. Restore the snapshot in the staging account.
  B. Copy the automated snapshot specifying a custom KMS encryption key. Share both the copied snapshot and the custom KMS encryption key with the staging account. Restore the snapshot to the staging account within the same Region.

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  Explanation/Reference:

  https://aws.amazon.com/premiumsupport/knowledge-center/rds-snapshots- share-account/

• Question 235:

  For the first time, a database professional is establishing a test graph database on Amazon Neptune. The database expert must input millions of rows of test observations from an Amazon S3.csv file. The database professional uploaded the data to the Neptune DB instance through a series of API calls.

  Which sequence of actions enables the database professional to upload the data most quickly? (Select three.)

  A. Ensure Amazon Cognito returns the proper AWS STS tokens to authenticate the Neptune DB instance to the S3 bucket hosting the CSV file.
  B. Ensure the vertices and edges are specified in different .csv files with proper header column formatting.
  C. Use AWS DMS to move data from Amazon S3 to the Neptune Loader.
  D. Curl the S3 URI while inside the Neptune DB instance and then run the addVertex or addEdge commands.
  E. Ensure an IAM role for the Neptune DB instance is configured with the appropriate permissions to allow access to the file in the S3 bucket.
  F. Create an S3 VPC endpoint and issue an HTTP POST to the databaseTMs loader endpoint.
  B. Ensure the vertices and edges are specified in different .csv files with proper header column formatting.
  E. Ensure an IAM role for the Neptune DB instance is configured with the appropriate permissions to allow access to the file in the S3 bucket.
  F. Create an S3 VPC endpoint and issue an HTTP POST to the databaseTMs loader endpoint.

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  Explanation/Reference:

  https://docs.aws.amazon.com/neptune/latest/userguide/bulk-load- optimize.html

• Question 236:

  A gaming company uses Amazon Aurora Serverless for one of its internal applications. The company's developers use Amazon RDS Data API to work with the Aurora Serverless DB cluster. After a recent security review, the company is mandating security enhancements. A database specialist must ensure that access to RDS Data API is private and never passes through the public internet.

  What should the database specialist do to meet this requirement?

  A. Modify the Aurora Serverless cluster by selecting a VPC with private subnets.
  B. Modify the Aurora Serverless cluster by unchecking the publicly accessible option.
  C. Create an interface VPC endpoint that uses AWS PrivateLink for RDS Data API.
  D. Create a gateway VPC endpoint for RDS Data API.
  C. Create an interface VPC endpoint that uses AWS PrivateLink for RDS Data API.

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  Explanation/Reference:

  https://aws.amazon.com/about-aws/whats-new/2020/02/amazon-rds-data- api-now-supports-aws-privatelink/

• Question 237:

  A company migrated one of its business-critical database workloads to an Amazon Aurora Multi-AZ DB cluster. The company requires a very low RTO and needs to improve the application recovery time after database failovers.

  Which approach meets these requirements?

  A. Set the max_connections parameter to 16,000 in the instance-level parameter group.
  B. Modify the client connection timeout to 300 seconds.
  C. Create an Amazon RDS Proxy database proxy and update client connections to point to the proxy endpoint.
  D. Enable the query cache at the instance level.
  C. Create an Amazon RDS Proxy database proxy and update client connections to point to the proxy endpoint.

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  Explanation/Reference:

  Amazon RDS Proxy allows applications to pool and share connections established with the database, improving database efficiency and application scalability. With RDS Proxy, failover times for Aurora and RDS databases are reduced by up

  to 66% and database credentials, authentication, and access can be managed through integration with AWS Secrets Manager and AWS Identity and Access Management (IAM).

  https://aws.amazon.com/rds/proxy/

• Question 238:

  A Database Specialist is creating Amazon DynamoDB tables, Amazon CloudWatch alarms, and associated infrastructure for an Application team using a development AWS account.

  The team wants a deployment method that will standardize the core solution components while managing environment- specific settings separately, and wants to minimize rework due to configuration errors.

  Which process should the Database Specialist recommend to meet these requirements?

  A. Organize common and environmental-specific parameters hierarchically in the AWS Systems Manager Parameter Store, then reference the parameters dynamically from an AWS CloudFormation template. Deploy the CloudFormation stack using the environment name as a parameter.
  B. Create a parameterized AWS CloudFormation template that builds the required objects. Keep separate environment parameter files in separate Amazon S3 buckets. Provide an AWS CLI command that deploys the CloudFormation stack directly referencing the appropriate parameter bucket.
  C. Create a parameterized AWS CloudFormation template that builds the required objects. Import the template into the CloudFormation interface in the AWS Management Console. Make the required changes to the parameters and deploy the CloudFormation stack.
  D. Create an AWS Lambda function that builds the required objects using an AWS SDK. Set the required parameter values in a test event in the Lambda console for each environment that the Application team can modify, as needed. Deploy the infrastructure by triggering the test event in the console.
  A. Organize common and environmental-specific parameters hierarchically in the AWS Systems Manager Parameter Store, then reference the parameters dynamically from an AWS CloudFormation template. Deploy the CloudFormation stack using the environment name as a parameter.

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  Explanation/Reference:

  https://aws.amazon.com/blogs/mt/integrating-aws-cloudformation-with-aws-systems- manager-parameter-store/

• Question 239:

  A company has a database fleet that includes an Amazon RDS for MySQL DB instance. During an audit, the company discovered that the data that is stored on the DB instance is unencrypted.

  A database specialist must enable encryption for the DB instance. The database specialist also must encrypt all connections to the DB instance.

  Which combination of actions should the database specialist take to meet these requirements? (Choose three.)

  A. In the RDS console, choose Enable encryption to encrypt the DB instance by using an AWS Key Management Service (AWS KMS) key.
  B. Encrypt the read replica of the unencrypted DB instance by using an AWS Key Management Service (AWS KMS) key. Fail over the read replica to the primary DB instance.
  C. Create a snapshot of the unencrypted DB instance. Encrypt the snapshot by using an AWS Key Management Service (AWS KMS) key. Restore the DB instance from the encrypted snapshot. Delete the original DB instance.
  D. Require SSL connections for applicable database user accounts.
  E. Use SSL/TLS from the application to encrypt a connection to the DB instance.
  F. Enable SSH encryption on the DB instance.
  A. In the RDS console, choose Enable encryption to encrypt the DB instance by using an AWS Key Management Service (AWS KMS) key.
  C. Create a snapshot of the unencrypted DB instance. Encrypt the snapshot by using an AWS Key Management Service (AWS KMS) key. Restore the DB instance from the encrypted snapshot. Delete the original DB instance.
  E. Use SSL/TLS from the application to encrypt a connection to the DB instance.

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  Explanation/Reference:

  https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Overview.Encryption.html#Ov erview.Encryption.Enabling

• Question 240:

  A database specialist deployed an Amazon RDS DB instance in Dev-VPC1 used by their development team. Dev-VPC1 has a peering connection with Dev-VPC2 that belongs to a different development team in the same department. The networking team confirmed that the routing between VPCs is correct; however, the database engineers in Dev-VPC2 are getting a timeout connections error when trying to connect to the database in Dev- VPC1.

  What is likely causing the timeouts?

  A. The database is deployed in a VPC that is in a different Region.
  B. The database is deployed in a VPC that is in a different Availability Zone.
  C. The database is deployed with misconfigured security groups.
  D. The database is deployed with the wrong client connect timeout configuration.
  C. The database is deployed with misconfigured security groups.

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  Explanation/Reference:

  "A VPC peering connection is a networking connection between two VPCs that enables you to route traffic between them using private IP addresses. Instances in either VPC can communicate with each other as if they are within the same network. You can create a VPC peering connection between your own VPCs, with a VPC in another AWS account, or with a VPC in a different AWS Region." https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/ USER_VPC.Scenarios.html